08.31.00
2 p.m. CDT, Thursday, August 31, 2000
Mission Control Center, Houston, Texas
STATUS REPORT: ISS00-40
INTERNATIONAL SPACE STATION STATUS REPORT #00-40
With a visit by the Space Shuttle Atlantis a little over a week away,
International Space Station flight controllers plan to conduct a
final rehearsal of the station's activities for the upcoming docking
on Tuesday.
This week, station controllers completed transferring propellants from
tanks aboard the attached Progress cargo craft to tanks aboard the
Zvezda living quarters module. Controllers in the United States and
Russia also conducted a test of the efficiency of the solar arrays on
the Zvezda and Zarya modules, finding everything in good shape.
An evaluation of problems with two batteries on the station -- one in
Zarya and one in Zvezda -- continued this week, although the problems
have no impact on any planned station activities. The problem
exhibited by the battery in Zarya, labeled Battery 6, is consistent
with normal signs of aging, and battery 6 is already planned to be
replaced during Atlantis' visit. The problem with the battery in
Zvezda, called Battery 4, is believed to be caused by an electronics
unit, called the PTAB, that is associated with the battery's charging
and discharging. The problem is not believed to be with the battery
itself. At present, Battery 4 is not in use, and the PTAB is planned
to be replaced during Atlantis' visit. The four other batteries
aboard Zvezda are operating normally.
Late last week, one of the three flight control computers aboard
Zvezda was automatically taken off line. To backup one another, three
computers operate simultaneously aboard the module, performing the
same functions. The other two computers are on line and continuing to
operate well and there is no impact to the station's activities. The
station can operate on only one computer if necessary, and the
docking of Atlantis could proceed using ground commanding to control
the station even if no computer was on-line. Analysts at the Russian
Mission Control Center in Korolev have dumped the off-line computer's
software and are evaluating it. Since the computer has been off-line,
it has remained operating and controllers have seen no other
problems.
As they continue to evaluate the station's orbit in preparation for
the rendezvous of Atlantis, station flight controllers will make a
final decision this weekend on whether a final engine firing
tentatively planned next week will be needed. On Tuesday, controllers
will briefly maneuver the station to the orientation required for the
Shuttle docking in a test of the docking procedures. On Sept. 8, the
day Atlantis is planned to launch from the Kennedy Space Center,
station controllers will turn on heaters to begin warming up the
Unity module in anticipation of the seven-member crew's arrival. With
a launch on Sept. 8, Atlantis is scheduled to dock with the station
at 1:12 a.m. CDT Sept. 10.
Now in an orbit with a high point of 228 statute miles and a low point
of 222 statute miles, the 67-ton, 143-foot long International Space
Station can easily be viewed from the ground under proper lighting
conditions. To see when the station is visible, check the human space
flight website at:
http://spaceflight.nasa.gov/realdata/sightings/
For updates on all aspects of human space flight, visit:
http://spaceflight.nasa.gov
The next Mission Control Center status report will be issued following
Atlantis' launch on Sept. 8 or as events warrant. For more
information, call the Johnson Space Center Newsroom at 281/483-5111.
-end-